Systemic lysosomal storage disease caused by a deficiency of alpha-L-iduronidase (iduronidase) and characterized by progressive physical deterioration with urinary excretion of dermatan sulfate and HEPARAN SULFATE. There are three recognized phenotypes representing a spectrum of clinical severity from severe to mild: Hurler syndrome, Hurler-Scheie syndrome and Scheie syndrome (formerly mucopolysaccharidosis V). Symptoms may include dwarfism; hepatosplenomegaly; thick, coarse facial features with low nasal bridge; corneal clouding; cardiac complications; and noisy breathing.